Guard Breaker

You have mastered the art of breaking an enemy’s guard, leaving them vulnerable to attacks. Once per turn, when you hit a creature with a melee attack for the second time in a turn, you can force that creature to make a Strength saving throw. The DC is equal to 8 + your proficiency bonus + your Strength or Dexterity modifier (your choice when you choose this feat). A creature immune to the prone condition automatically succeeds on this save. On a failed save, that creature can’t benefit from a shield until the start of your next turn, and can’t add their Dexterity modifier to their AC.